I see a black screen that says "GEN" in the bottom right hand corner, what gives?

This should be fixed very soon, this is a development screen that is left over from an earlier version that's accessed by shaking the phone/tablet. If you follow these instructions from Apple you should have TouchTone working again.

I'm in the city/hill and I can't see any words to go with the phone call.

This is a bug on our end, we've submitted a fix and expect it to go live a couple days after release. For the time being you should be able to progress by closing out of the call. Once you get the new version you can go back to the calls and fill in the gaps. Sorry about this!

What's with the text in the 3rd tutorial that says "Unhandled Exception: System.NullReferenceException:" etc.?

This isn't a bug! We meant to do that. That's all we can really say about that though!